Angiotensin I converting enzyme (ACE1, EC: 3.4.15.1), a dipeptidyl carboxypeptidase, is part of the renin-angiotensin system (RAS) that controls regulation of blood pressure by cleaving the C-terminal dipeptides of angiotensin I and bradykinin. It is found on the luminal surface of vascular endothelial cells, especially in pulmonary tissues. Elevated levels of ACE1 are found in patients suffering from sarcoidosis, leprosy, hyperthyroidism, acute hepatitis, primary biliary cirrhosis, diabetes mellitus, multiple myeloma, osteoarthritis, amyloidosis, Gaucher's disease, pneumoconiosis, histoplasmosis and miliary tuberculosis. Assay Genie's ACE1 Activity Assay Kit utilizes an active ACE1 to cleave a synthetic o-aminobenzoyl peptide (Abz-based peptide) substrate to release a fluorophore. The released Abz can be easily quantified using a fluorescence microplate reader. This assay kit is simple, rapid and can detect ACE activity as low as 10 mU in biological samples

Figure: (a) Abz-Standard Curve (0-1000 pmol), error bars indicate SD (n=3). (b) Kinetic activity curves using different amounts of ACE1 Positive Control in the assay. (c) ACE1 activity was measured for different types of rat tissue samples (lung, heart and kidney; 0.6 µg each). Assays were performed following the kit protocol.